No, it comes with a QD sling attachment, but no rail section.
Unfortunately the exact dimensions of that gas block are not provided by POF. You will need to verify fitment with POF, but it will very likely be compatible.
The Bravo Company MFG MCMR M-LOK Handguard will work with all gas system lengths as long as you are using a low-profile gas block. Ignore the gas system length, we are updating the page.
No, the Bravo Company MFG MCMR M-LOK Handguard has an internal diameter of 1.3", which is not large enough to accommodate adjustable gas blocks.
The Bravo Company MFG MCMR M-LOK Handguard (MPN:MCMR13556BLK) is listed as being 13.4" as that is the overall length when measured to the flare.
The 13.4" Bravo Company MFG MCMR M-LOK Handguard would work fine with your 13.9" barrel as long as you do not plan on using a suppressor which will interfere with the handguard.
Yes, the Bravo Company MFG MCMR M-LOK Handguard will fit the M4E1 upper receiver as your upper works with standard AR15 components. Barrel nut and mounting hardware are included in order to install the handguard.
The Bravo Company MFG MCMR M-LOK Handguard is designed to fit Mil-spec pattern AR15 upper receivers. If you have a delta ring and fixed front sight, they must be removed in order to install this handguard.
No, the Bravo Company MFG MCMR M-LOK Handguard will not be compatible.
So the Bravo Company MFG MCMR M-LOK Handguard that says 7.39" is the length of the handguard. So the handguard may be the length you want but the gas system will be too long.